Preparation method of protein composite emulsion gel added with dietary fibers
Through magnetic stirring and Ca+-TG enzyme cross-linking method, protein and dietary fiber composite emulsion gel is prepared, which solves the problems of high energy consumption, high production costs and unstable gel structure in the prior art, and achieves dense and stable gel structure and low-cost and efficient preparation.
Patent Information
- Application Number
- CN202510347761.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-24
- Publication Date
- 2025-05-06
AI Technical Summary
In the prior art, when preparing protein composite emulsion gels, the energy consumption is high, the production cost is high, and the gel structure is unstable and difficult to control.
Magnetic stirring is used to make the protein and dietary fiber fully contact to form a non-covalent interaction complex structure, and then a dense and stable protein complex emulsion gel is prepared by heating and Ca+-TG enzyme cross-linking method.
The dense and stable structure of the protein composite emulsion gel is realized, which reduces production costs, improves the solidification efficiency, and improves the chewability of the gel and the embedding loading effect of functional components.
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Abstract
Description
Technical Field
[0001] The invention relates to a method for preparing a dietary fiber-added protein composite emulsion gel, and belongs to the application field of protein-based functional foods. Background Art
[0002] With the rapid growth of the global population and the increasing demand for health and nutritious diets, the demand for protein in food is increasing worldwide. As excessive intake of animal protein poses serious challenges to the environment, health and cost, the research on sustainable plant protein is gradually growing. On the one hand, plant protein has the advantages of being free of harmful ingredients such as allergens and cholesterol and being inexpensive; on the other hand, the gelling properties of plant protein make it often used to replace casein in the production of coagulated dairy products such as cheese and yogurt. Plant protein-based emulsion gel can also be used as one of the main fat substitutes in food processing and is widely used in the research and development of functional foods for people with glucose and lipid metabolism disorders. Therefore, the research and application of new plant protein functional foods have become more and more extensive. However, a single protein component often cannot meet the needs of specific foods, and polysaccharides and other substances are usually introduced to modify the protein to improve the various functional properties of the protein.
[0003] At present, long-term high-sugar and high-fat diets and low dietary fiber intake can easily cause metabolic diseases mainly characterized by glucose and lipid metabolism disorders, such as decreased liver function, tumors, cardiovascular diseases, diabetes, kidney disease, etc., which seriously threaten human health. Dietary fiber is not decomposed and absorbed by human digestive enzymes, but can be fermented into beneficial substances by beneficial bacteria in the large intestine, which has the effect of lowering blood sugar and blood lipids in the body, and thus has received extensive attention in the research of functional foods for people with glucose and lipid metabolism disorders. Studies have shown that soluble dietary fiber is a polysaccharide with heterogeneous branches. Because of its good water retention, gelation and a series of functional properties that are beneficial to human health, it can improve the texture characteristics of protein-based emulsion gels without affecting the flavor of the gel. However, the preparation of protein-dietary fiber composite emulsion gels generally adopts direct heating treatment to form hot gels or heat denaturation of the solution, and then adds enzymes or salt ions and other coagulants to form cold gels. The method of preparing hot gel consumes a lot of energy and the temperature is difficult to control; the method of preparing cold gel requires the addition of enzymes, which is expensive and has high production costs. Although adding salt ions can reduce costs, lower or higher concentrations of salt ions will affect the formation of gel, and the concentration is difficult to control, which is not conducive to the preparation of gel. Summary of the invention
[0004] In view of the deficiencies in the prior art, the object of the present invention is to provide a method for preparing a protein composite emulsion gel with added dietary fiber, which has low production cost and high coagulation efficiency, and the obtained protein composite emulsion gel with added dietary fiber has a dense and stable structure.
[0005] In order to solve the above technical problems, the technical solution provided by the present invention is: A method for preparing a protein composite emulsion gel with added dietary fiber comprises the following steps: (1) Preparation of protein suspension: Add protein powder to water and stir evenly to obtain protein suspension; (2) Preparation of hydrated protein solution: magnetically stirring the protein suspension to fully hydrate it to obtain a hydrated protein solution; (3) Preparation of protein-dietary fiber solution: adding soluble dietary fiber to the hydrated protein solution and stirring the mixture thoroughly with a magnetic stirrer to obtain a protein-dietary fiber solution; (4) Preparation of protein composite emulsion: heat the protein-dietary fiber solution in a boiling water bath for 10-15 min, adjust the pH to 6.0-6.5 with HCl solution, add medium-chain triglycerides, and emulsify with a high-pressure homogenizer to obtain a protein composite emulsion; (5) Preparation of protein composite emulsion gel: Add CaCl2 solution and glutamine transaminase solution to the protein composite emulsion, stir evenly, and heat it in a water bath to obtain a protein composite emulsion gel; (6) Inactivating the enzyme: placing the protein composite emulsion gel in a water bath at 80-90°C and heating it for 10-20 minutes to obtain the protein composite emulsion gel after inactivating the enzyme; (7) Termination of the reaction: The protein composite emulsion gel after the enzyme inactivation is cooled to room temperature, and then stored at low temperature to obtain a protein composite emulsion gel with added dietary fiber.
[0006] Furthermore, in step (1), the mass ratio of the protein powder to water is 1:(3-5).
[0007] Furthermore, in step (1), the mass ratio of the protein powder to water is 1:4.
[0008] Furthermore, in step (1), the protein powder includes soy protein powder, hemp seed protein powder, pea protein powder, and phycocyanin powder.
[0009] Furthermore, in step (2), the stirring temperature is 20-30° C., the stirring time is 50-70 min, and the stirring speed is 400-600 r / min.
[0010] Furthermore, in step (2), the stirring temperature is 25° C., the stirring time is 60 min, and the stirring speed is 500 r / min.
[0011] Furthermore, in step (3), the mass ratio of the soluble dietary fiber to the hydrated protein solution is 1:(8-10); the mass ratio of the medium-chain triglyceride to the hydrated protein solution is 1:(2-4). Adding a certain amount of dietary fiber can improve the gel structure, make the gel network denser, and improve water retention and other properties. Excessive addition will lead to excessive water content in the gel and reduced gel strength. Medium-chain triglycerides mainly play an emulsifying role, and excessive use will result in poor homogenization effect.
[0012] Furthermore, in step (3), the mass ratio of the soluble dietary fiber to the hydrated protein solution is 1:9; and the mass ratio of the medium chain triglyceride to the hydrated protein solution is 1:3.
[0013] Furthermore, in step (3), the stirring temperature is 20-30°C, the stirring time is 25-35min, and the stirring speed is 400-600r / min. Through magnetic stirring, the protein and dietary fiber are fully in contact, and non-covalent interaction occurs between the two, forming a composite structure with the protein skeleton as the network body and the dietary fiber as the filler, wherein the dietary fiber can enhance the compactness of the protein main structure, thereby improving its various properties.
[0014] Furthermore, in step (3), the stirring temperature is 25° C., the stirring time is 30 min, and the stirring speed is 500 r / min.
[0015] Furthermore, in step (4), the concentration of the HCl solution is 0.5-1.5 mol / L.
[0016] Furthermore, in step (4), the concentration of the HCl solution is 1 mol / L.
[0017] Furthermore, in step (4), the speed of the high-pressure homogenizer is 10000 r / min, the temperature of the high-pressure homogenizer is 25° C., and the pressure of the high-pressure homogenizer is 20 MPa. Heating allows the protein molecules to fully unfold and their network skeletons to denature.
[0018] Furthermore, in step (4), the emulsification time is 3-5 minutes and the emulsification times are 2 times.
[0019] Furthermore, in step (4), the emulsification time is 3 minutes.
[0020] Furthermore, in step (5), the concentration of CaCl2 in the protein composite emulsion is 8-12 mmol / L, and the concentration of transglutaminase in the protein composite emulsion is 25-35 U / g.
[0021] Furthermore, in step (5), the concentration of CaCl2 in the protein composite emulsion is 10 mmol / L, and the concentration of transglutaminase in the protein composite emulsion is 30 U / g.
[0022] Ca + It destroys the negative charge on the protein surface and bridges with the hydrogen ions on the protein carboxyl group to form a dense structure, and effectively avoids the aggregation and hydration of droplets. TG enzyme exposes the hydrophobic groups inside the protein molecules, enhances the hydrophobic interaction between the components, and can also cause the lysine residues and glutamic acid residues in the protein to undergo transacylation reactions, and covalent crosslinking occurs between the protein molecules to obtain a dense and stable protein composite emulsion gel. Heating can fully expose the sulfhydryl and hydrophobic groups in the protein, and form a network gel structure through hydrogen bonds and hydrophobic interactions. However, excessive calcium ion concentration will cause the static charge on the protein surface to be neutralized, and the protein molecules will form aggregates through hydrogen bonds, which is not conducive to the interaction between protein molecules, and its addition and effect are limited; the improvement effect of TG enzyme will not increase with the increase in the amount of addition, but excessive will affect the protein network structure due to occupying the protein molecule site, and its crosslinking effect is limited. Therefore, the use of calcium ions and TG enzymes at the same time can obtain better crosslinking effects.
[0023] Furthermore, in step (5), the water bath heating temperature is 50° C. and the heating time is 120 min.
[0024] Furthermore, in step (7), the low-temperature storage time is 12 hours, and the low-temperature storage temperature is 4° C. Low-temperature storage ensures that the gel is fully formed.
[0025] The medium chain triglyceride is referred to as MCT oil; transglutaminase is referred to as TG enzyme.
[0026] The method disperses protein and dietary fiber in water, stirs at a certain speed and time to achieve full contact between the protein and dietary fiber, promotes non-covalent interaction between the two components, and then denatures the protein network skeleton by heating. + - Preparation of emulsion gel by TG enzyme cross-linking method, Ca + It destroys the negative charge on the protein surface and bridges with the hydrogen ions on the protein carboxyl groups to form a dense structure and effectively avoid droplet aggregation and hydration. TG enzyme exposes the hydrophobic groups inside the protein molecules, enhances the hydrophobic interaction between the components, and produces a dense and stable protein composite emulsion gel.
[0027] Compared with the prior art, the present invention has the following beneficial effects: (1) The protein composite emulsion gel with added dietary fiber prepared by the present invention has a dense and stable network gel structure, which can improve the various properties of the emulsion gel. In the application of protein-based functional foods, it has better chewing properties and can also improve the embedding loading effect of the emulsion gel on functional ingredients.
[0028] (2) The present invention uses Ca + -TG enzyme cross-linking method can effectively control the degree of protein denaturation and avoid the problem of gel structure damage caused by insufficient or excessive heating; and the combined use of salt ions and enzymes not only reduces the use of enzymes and reduces costs, but also enhances the coagulation efficiency of salt ions.
[0029] (3) No organic solvent is introduced in the preparation process of the present invention, which can effectively avoid environmental pollution. The production process is simple, highly operable, and carried out in a closed manner at room temperature. The equipment cost is low and mass production is possible. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 This is a structural diagram of the protein composite emulsion gel with dietary fiber added in Example 1, magnified to 500 μm; Figure 2 This is a structural diagram of the protein composite emulsion gel with dietary fiber added in Example 1, magnified to 50 μm; Figure 3 This is a structural diagram of the protein composite emulsion gel with dietary fiber added in Example 2, magnified to 500 μm; Figure 4 This is a structural diagram of the protein composite emulsion gel with dietary fiber added in Example 2, magnified to 50 μm; Figure 5 This is a structural diagram of the protein composite emulsion gel with dietary fiber added in Example 3, magnified to 500 μm; Figure 6 This is a structural diagram of the protein composite emulsion gel with dietary fiber added in Example 3, magnified to 50 μm; Figure 7 This is a structural diagram of the protein composite emulsion gel with dietary fiber added in Example 4, magnified to 500 μm; Figure 8 This is a structural diagram of the protein composite emulsion gel with dietary fiber added in Example 4, magnified to 50 μm; Fig. 9 This is a comparison chart of the effects of vitamin D3 embedded in emulsion gel in Experimental Example 3. DETAILED DESCRIPTION
[0031] Example 1 A method for preparing a protein composite emulsion gel with added dietary fiber comprises the following steps: (1) Preparation of protein suspension: Accurately weigh 20 parts of soybean protein powder, add it to 80 parts of water, and stir evenly to obtain a protein suspension; (2) Preparation of hydrated protein solution: The protein suspension was subjected to magnetic stirring to fully hydrate the protein suspension. The magnetic stirring temperature was 25°C, the time was 60 min, and the speed was 500 r / min to obtain a hydrated protein solution. (3) Preparation of protein-dietary fiber solution: Add 10 parts of soluble dietary fiber to 90 parts of hydrated protein solution and stir thoroughly with a magnetic stirrer at a temperature of 25°C, a time of 30 minutes, and a speed of 500 r / min to obtain a protein-dietary fiber solution; (4) Preparation of protein composite emulsion: The protein-dietary fiber solution was placed in a boiling water bath and heated for 10 min, the pH was adjusted to 6.0 with 1 mol / L HCl solution, 30 parts of medium-chain triglycerides were added, and emulsification was performed using a high-pressure homogenizer. The speed of the high-pressure homogenizer was 10,000 r / min, the temperature was 25°C, the pressure was 20 MPa, the emulsification time was 3 min, and the emulsification was repeated twice to obtain a protein composite emulsion; (5) Preparation of protein composite emulsion gel: Add CaCl2 solution and transglutaminase solution to the protein composite emulsion, stir evenly, and heat it in a water bath at 50°C for 120 min to obtain a protein composite emulsion gel; the concentration of CaCl2 in the protein composite emulsion is 10 mmol / L, and the concentration of transglutaminase is 30 U / g; (6) Inactivating the enzyme: placing the protein composite emulsion gel in a water bath at 85°C for 15 min to obtain the protein composite emulsion gel after inactivating the enzyme; (7) Termination of the reaction: The protein composite emulsion gel after the enzyme inactivation is cooled to room temperature, and then stored at a low temperature of 4°C for 12 hours to obtain a protein composite emulsion gel with added dietary fiber.
[0032] Example 2 A method for preparing a protein composite emulsion gel with added dietary fiber comprises the following steps: (1) Preparation of protein suspension: Accurately weigh 20 parts of hemp seed protein powder, add it to 80 parts of water, and stir evenly to obtain a protein suspension; (2) Preparation of hydrated protein solution: The protein suspension was subjected to magnetic stirring to fully hydrate the protein suspension. The magnetic stirring temperature was 25°C, the time was 60 min, and the speed was 500 r / min to obtain a hydrated protein solution. (3) Preparation of protein-dietary fiber solution: Add 10 parts of soluble dietary fiber to 90 parts of hydrated protein solution and stir thoroughly with a magnetic stirrer at a temperature of 25°C, a time of 30 minutes, and a speed of 500 r / min to obtain a protein-dietary fiber solution; (4) Preparation of protein composite emulsion: The protein-dietary fiber solution was placed in a boiling water bath and heated for 10 min, the pH was adjusted to 6.0 with 1 mol / L HCl solution, 30 parts of medium-chain triglycerides were added, and emulsification was performed using a high-pressure homogenizer. The speed of the high-pressure homogenizer was 10,000 r / min, the temperature was 25°C, the pressure was 20 MPa, the emulsification time was 3 min, and the emulsification was repeated twice to obtain a protein composite emulsion; (5) Preparation of protein composite emulsion gel: Add CaCl2 solution and transglutaminase solution to the protein composite emulsion, stir evenly, and heat it in a water bath at 50°C for 120 min to obtain a protein composite emulsion gel; the concentration of CaCl2 in the protein composite emulsion is 10 mmol / L, and the concentration of transglutaminase is 30 U / g; (6) Inactivating the enzyme: placing the protein composite emulsion gel in a water bath at 85°C for 15 min to obtain the protein composite emulsion gel after inactivating the enzyme; (7) Termination of the reaction: The protein composite emulsion gel after the enzyme inactivation is cooled to room temperature, and then stored at a low temperature of 4°C for 12 hours to obtain a protein composite emulsion gel with added dietary fiber.
[0033] Example 3 A method for preparing a protein composite emulsion gel with added dietary fiber comprises the following steps: (1) Preparation of protein suspension: Accurately weigh 20 parts of pea protein powder, add it to 80 parts of water, and stir evenly to obtain a protein suspension; (2) Preparation of hydrated protein solution: The protein suspension was subjected to magnetic stirring to fully hydrate the protein suspension. The magnetic stirring temperature was 25°C, the time was 60 min, and the speed was 500 r / min to obtain a hydrated protein solution. (3) Preparation of protein-dietary fiber solution: Add 10 parts of soluble dietary fiber to 90 parts of hydrated protein solution and stir thoroughly with a magnetic stirrer at a temperature of 25°C, a time of 30 minutes, and a speed of 500 r / min to obtain a protein-dietary fiber solution; (4) Preparation of protein composite emulsion: The protein-dietary fiber solution was placed in a boiling water bath and heated for 10 min, the pH was adjusted to 6.0 with 1 mol / L HCl solution, 30 parts of medium-chain triglycerides were added, and emulsification was performed using a high-pressure homogenizer. The speed of the high-pressure homogenizer was 10,000 r / min, the temperature was 25°C, the pressure was 20 MPa, the emulsification time was 3 min, and the emulsification was repeated twice to obtain a protein composite emulsion; (5) Preparation of protein composite emulsion gel: Add CaCl2 solution and transglutaminase solution to the protein composite emulsion, stir evenly, and heat it in a water bath at 50°C for 120 min to obtain a protein composite emulsion gel; the concentration of CaCl2 in the protein composite emulsion is 10 mmol / L, and the concentration of transglutaminase is 30 U / g; (6) Inactivating the enzyme: placing the protein composite emulsion gel in a water bath at 85°C for 15 min to obtain the protein composite emulsion gel after inactivating the enzyme; (7) Termination of the reaction: The protein composite emulsion gel after the enzyme inactivation is cooled to room temperature, and then stored at a low temperature of 4°C for 12 hours to obtain a protein composite emulsion gel with added dietary fiber.
[0034] Example 4 A method for preparing a protein composite emulsion gel with added dietary fiber comprises the following steps: (1) Preparation of protein suspension: Accurately weigh 20 parts of phycocyanin powder, add it to 80 parts of water, and stir evenly to obtain a protein suspension; (2) Preparation of hydrated protein solution: The protein suspension was subjected to magnetic stirring to fully hydrate the protein suspension. The magnetic stirring temperature was 25°C, the time was 60 min, and the speed was 500 r / min to obtain a hydrated protein solution. (3) Preparation of protein-dietary fiber solution: Add 10 parts of soluble dietary fiber to 90 parts of hydrated protein solution and stir thoroughly with a magnetic stirrer at a temperature of 25°C, a time of 30 minutes, and a speed of 500 r / min to obtain a protein-dietary fiber solution; (4) Preparation of protein composite emulsion: The protein-dietary fiber solution was placed in a boiling water bath and heated for 10 min, the pH was adjusted to 6.0 with 1 mol / L HCl solution, 30 parts of MCT oil were added, and emulsified with a high-pressure homogenizer. The speed of the high-pressure homogenizer was 10000 r / min, the temperature was 25°C, the pressure was 20 MPa, the emulsification time was 3 min, and the emulsification was repeated twice to obtain a protein composite emulsion; (5) Preparation of protein composite emulsion gel: Add CaCl2 solution and transglutaminase solution to the protein composite emulsion, stir evenly, and heat it in a water bath at 50°C for 120 min to obtain a protein composite emulsion gel; the concentration of CaCl2 in the protein composite emulsion is 10 mmol / L, and the concentration of transglutaminase is 30 U / g; (6) Inactivating the enzyme: placing the protein composite emulsion gel in a water bath at 85°C for 15 min to obtain the protein composite emulsion gel after inactivating the enzyme; (7) Termination of the reaction: The protein composite emulsion gel after the enzyme inactivation is cooled to room temperature, and then stored at a low temperature of 4°C for 12 hours to obtain a protein composite emulsion gel with added dietary fiber.
[0035] Comparative Example 1 In step (5), no CaCl2 solution and transglutaminase solution are added, and the remaining steps are the same as those in Example 1, except that: (5) Preparation of protein composite emulsion gel: The protein composite emulsion was stirred evenly and heated in a water bath at 50°C for 120 min to obtain a protein composite emulsion gel.
[0036] Comparative Example 2 In step (5), no CaCl2 solution is added, and the remaining steps are the same as those in Example 1, except that: (5) Preparation of protein composite emulsion gel: Add glutamine transaminase solution to the protein composite emulsion, stir evenly, and heat it in a water bath at 50°C for 120 min to obtain a protein composite emulsion gel; the concentration of glutamine transaminase in the protein composite emulsion is 30 U / g.
[0037] Comparative Example 3 In step (5), no transglutaminase solution is added, and the remaining steps are the same as those in Example 1, except that: (5) Preparation of protein composite emulsion gel: Add CaCl2 solution to the protein composite emulsion, stir evenly, and heat it in a water bath at 50°C for 120 min to obtain a protein composite emulsion gel; the concentration of CaCl2 in the protein composite emulsion is 10 mmol / L.
[0038] Comparative Example 4 In step (5), no CaCl2 solution is added, but a large amount of transglutaminase solution is added. The remaining steps are the same as those in Example 1, except that: (5) Preparation of protein composite emulsion gel: adding transglutaminase solution to the protein composite emulsion, stirring evenly, and heating the emulsion in a water bath at a temperature of 50° C. for 120 min to obtain a protein composite emulsion gel; the concentration of transglutaminase in the protein composite emulsion is 40 U / g; Comparative Example 5 In step (5), no transglutaminase solution was added, but a large amount of CaCl2 solution was added. The remaining steps were the same as those in Example 1, except that: (5) Preparation of protein composite emulsion gel: Add CaCl2 solution to the protein composite emulsion, stir evenly, and heat it in a water bath at 50°C for 120 min to obtain a protein composite emulsion gel; the concentration of CaCl2 in the protein composite emulsion is 15 mmol / L.
[0039] Comparative Example 6 In step (3), no soluble dietary fiber is added, and the remaining steps are the same as those in Example 1, except that: (3) Preparation of protein solution: 90 parts of hydrated protein solution were fully stirred using a magnetic stirrer at a temperature of 25°C, a time of 30 min, and a speed of 500 r / min to obtain a protein-dietary fiber solution.
[0040] Experimental Example 1 The properties of the protein composite emulsion gels with dietary fiber added in Examples 1-4 were tested. The test results are listed in Table 1. The gel structures are shown in the attached table. Figure 1-8 .
[0041] Table 1. Properties of protein composite emulsion gels with added dietary fiber As shown in Table 1, the soybean protein gel prepared by adding enzyme and calcium ion at the same time in Examples 1-4 using the calcium ion-TG enzyme crosslinking method has high hardness, high chewiness and high cohesion. The scanning electron microscope FlexSEM1000 was used to observe the gel at magnifications of 500 μm and 50 μm respectively. Figure 1-8 It can be seen that the protein composite emulsion gel with dietary fiber added prepared by the present invention has a good structure, is compact and stable. It can be seen that the method of the present invention can effectively control the degree of protein denaturation and prepare a protein composite emulsion gel with a compact and stable structure.
[0042] Experimental Example 2 The performance of the protein composite emulsion gel with added dietary fiber in Example 1 and Comparative Examples 1-6 was tested, and the coagulation effect of the protein composite emulsion gel during the process of Example 1 and Comparative Examples 1-6 was observed. The observation results are listed in Table 2.
[0043] Table 2. Properties and coagulation effects of protein composite emulsion gels As can be seen from Table 2, Example 1 adds TG enzyme and calcium ions at the same time, and the soy protein gel prepared by the calcium ion-TG enzyme crosslinking method has a hardness of 278.5g, a chewiness of 95.6, and a cohesion of 0.43; Comparative Example 1 does not use the calcium ion-TG enzyme crosslinking method, and when the structure is formed only by heating, the hardness of the soy protein gel is 132.8g, the chewiness is 53.0, and the cohesion is 0.36; Comparative Example 2 uses only TG enzyme to prepare the gel, and the gel hardness is 143.5g, the chewiness is 63.2, and the cohesion is 0.39; Comparative Example 3 uses only calcium ions to prepare the gel, and the gel hardness is 143.5g, the chewiness is 63.2, and the cohesion is 0.39; It can be seen that the addition of TG enzyme and calcium ions will increase the hardness, chewiness and cohesion of the gel. However, Comparative Examples 4 and Comparative Examples 5 further increase the amount of TG enzyme or calcium ions added, which will cause a decrease in hardness, chewiness and cohesion. In Comparative Example 6, dietary fiber was not added, and the structure of the prepared gel was relatively loose, which shows that dietary fiber can further improve the structural density of the protein composite emulsion gel. It can be seen that the method of the present invention can effectively control the degree of protein denaturation, avoid the problem of gel structure damage caused by insufficient or excessive heating, and prepare a protein composite emulsion gel with a dense and stable structure.
[0044] It can be seen from the experiment that the coagulation efficiency of the protein composite emulsion gel in Example 1 is fast, and the gel is dense and stable. Comparative Example 1 does not add calcium ions and TG enzyme, and the coagulation efficiency of the protein composite emulsion gel is slow, and the gel texture is loose. Comparative Examples 2-6 all present similar conclusions, and the coagulation efficiency of the protein composite emulsion gel is low, the coagulation rate is slow, and the structure is relatively loose. It can be seen that the present invention adds calcium ions and TG enzyme at the same time, which can improve the coagulation efficiency of the protein composite emulsion gel and the structure of the gel, and improve the coagulation effect.
[0045] Experimental Example 3 The steps were the same as those in Example 1, except that no dietary fiber was added to prepare the soybean protein emulsion gel.
[0046] Vitamin D3 was encapsulated by using soybean protein emulsion gel and the protein composite emulsion gel with dietary fiber added in Example 1 (referred to as soybean protein-dietary fiber emulsion gel) to measure the effect of its delivery system. The test results are shown in Table 3 and Attached Fig. 9 .
[0047] Table 3. Effect of emulsion gel encapsulation of vitamin D3 From Table 3 and Appendix Fig. 9It can be seen that the soy protein emulsion gel prepared without adding dietary fiber has an embedding rate of vitamin D3 of about 79.5%, and the soy protein-dietary fiber emulsion gel prepared with adding dietary fiber has an embedding rate of vitamin D3 of about 86.4%. It can be seen that the emulsion gel prepared with adding dietary fiber has a higher embedding rate of vitamin D3, indicating that the emulsion gel prepared with adding dietary fiber of the present invention has a dense structure, is more suitable as an embedding material, and can replace food raw materials such as soy protein emulsion gel. The use effect after replacement is excellent, and the addition of dietary fiber can reduce blood sugar and blood lipids in the body, which is more beneficial to human health.
Claims
1. A method for preparing a protein composite emulsion gel with added dietary fiber, characterized in that: The following steps are involved: (1) Preparation of protein suspension: Add protein powder to water and stir evenly to obtain protein suspension; (2) Preparation of hydrated protein solution: magnetically stirring the protein suspension to fully hydrate it to obtain a hydrated protein solution; (3) Preparation of protein-dietary fiber solution: adding soluble dietary fiber to the hydrated protein solution and stirring the mixture thoroughly with a magnetic stirrer to obtain a protein-dietary fiber solution; (4) Preparation of protein composite emulsion: heat the protein-dietary fiber solution in a boiling water bath for 10-15 min, adjust the pH to 6.0-6.5 with HCl solution, add medium-chain triglycerides, and emulsify with a high-pressure homogenizer to obtain a protein composite emulsion; (5) Preparation of protein composite emulsion gel: Add CaCl2 solution and glutamine transaminase solution to the protein composite emulsion, stir evenly, and heat it in a water bath to obtain a protein composite emulsion gel; (6) Inactivating the enzyme: placing the protein composite emulsion gel in a water bath at 80-90°C and heating it for 10-20 minutes to obtain the protein composite emulsion gel after inactivating the enzyme; (7) Termination of the reaction: The protein composite emulsion gel after the enzyme inactivation is cooled to room temperature, and then stored at low temperature to obtain a protein composite emulsion gel with added dietary fiber.
2. The method for preparing the protein composite emulsion gel with added dietary fiber according to claim 1, characterized in that: In step (1), the mass ratio of the protein powder to water is 1:(3-5).
3. The method for preparing the protein composite emulsion gel with added dietary fiber according to claim 1, characterized in that: In step (2), the stirring temperature is 20-30° C., the stirring time is 50-70 min, and the stirring speed is 400-600 r / min.
4. The method for preparing the protein composite emulsion gel with added dietary fiber according to claim 3, characterized in that: In step (3), the mass ratio of the soluble dietary fiber to the hydrated protein solution is 1:(8-10); the mass ratio of the medium chain triglyceride to the hydrated protein solution is 1:(2-4).
5. The method for preparing the protein composite emulsion gel with added dietary fiber according to claim 1, characterized in that: In step (3), the stirring temperature is 20-30°C, the stirring time is 25-35min, and the stirring speed is 400-600r / min.
6. The method for preparing the protein composite emulsion gel with added dietary fiber according to claim 1, characterized in that: In step (4), the rotation speed of the high-pressure homogenizer is 10000 r / min, the temperature of the high-pressure homogenizer is 25° C., and the pressure of the high-pressure homogenizer is 20 MPa.
7. The method for preparing the protein composite emulsion gel with added dietary fiber according to claim 5 or 6, characterized in that: In step (4), the emulsification time is 3-5 minutes and the emulsification times are 2 times.
8. The method for preparing the protein composite emulsion gel with added dietary fiber according to claim 7, characterized in that: In step (5), the concentration of CaCl2 in the protein composite emulsion is 8-12 mmol / L, and the concentration of transglutaminase in the protein composite emulsion is 25-35 U / g.
9. The method for preparing the protein composite emulsion gel with added dietary fiber according to claim 1, characterized in that: In step (5), the water bath heating temperature is 50° C. and the heating time is 120 min.
10. The method for preparing the protein composite emulsion gel with added dietary fiber according to claim 9, characterized in that: In step (7), the low-temperature storage time is 12 hours, and the low-temperature storage temperature is 4°C.